Boxfish(Ostraciidae) have a unique square shape and a particular way of swimming.
They have a rather special personality, which one quickly comes to love.
Boxfish live typically off a mixture of algae, coral polyps, zooplankton, and in some cases crustaceans.
They are not normally reef safe and when small will require gentle water circulation.
Boxfish can secrete a poison when stressed or if they die, which can in the worst case, kill the contents of a whole aquarium.
Never use the water the fish was transported in.